prosthodontic implications of oral mucosa.pptx

PROSTHODONTIC IMPLICATIONS OF ORAL MUCOSA

1. PROSTHODONTIC IMPLICATIONS OF ORAL MUCOSA PRENISHA.F.P PG STUDENT

2. CONTENTS Introduction Biomechanics of oral mucosa Types of oral mucosa Types of Prosthesis Interaction of prosthetic materials with oral environment Removable prosthesis Fixed prosthesis Conclusion References

3. BIOMECHANICS OF ORAL MUCOSA During mastication, oral mucosa plays a critical role in distributing occlusal loads to the underlying bony ridge. Within this highly vascular tissue, the functional pressure namely interstitial fluid pressure or hydrostatic pressure is one of the most important etiological factors causing clinical complications. Chen J, Ahmad R, Li W, Swain M, Li Q. 2015 Biomechanics of oral mucosa. J. R. Soc. 2015;

4. Anatomical and physiological factors The masticatory mucosa comprises of a surface epithelial layer and a deeper connective tissue layer(lamina propria ). The underlying lamina propria is a compact fibrous tissue comprising of the papillary layer and the deeper reticular layer. The abundance of fibrous attachments, known as mucoperiosteum , renders the oral mucosa immovable with firm connection to the bone, resisting compression and shear in function.

5. Elasticity • Modulus of elasticity is the physical description of an object’s tendency to be deformed proportionally to the applied force . The oral mucosa was found to be highly deformable under compression, and the elastic modulus appears to vary over a broad range.

6. Viscosity and permeability • Accompanying the instant elastic responses, the oral mucosa also exhibits a dynamic response over the time under loading and upon unloading, interpreting as creep and delayed recovery . • Both the fluidic viscosity and permeability influence the dynamic response . • The mucosa in the elderly population often has more significant viscous behavior, and reduced rebound with delayed recovery because of the reduced amount of elastin . • Increasing contact areas generally leads to stiffer mucosal responses

7. Friction coefficient • The oral mucosa does not only sustain compressive loading, but also the surface shear induced by the friction beneath the dentures. • Denture-induced symptoms, such as traumatic ulcers, angular cheilitis , irritation hyperplasia and keratosis are related to the frictional loading on the mucosa. • With the same oral condition, the friction coefficient can also change between different denture materials. • A material with higher wettability will be more likely to form a superior lubricating layer between the supporting mucosal surface and the denture base, thus protecting the surface tissue by reduced friction.

8. Tissue displaceability • Some dentures distribute occlusal loads unevenly to multiple supporting tissues, such as the teeth (including the PDL), mucosa and bone around an implant. Examples are removable partial dentures and implant-retained overdentures . They obtain stiffer support compared to complete dentures. • Their different material properties contribute to the difference in denture displacement. • The displacement of the contact surface generally increases from the supporting tooth unit towards the distal extension resulting in stress concentrations in the underlying mucosa. The tissue displaceability difference does not only cause stress-induced pain, discomfort and bone resorption but also affects the long-term health of the remaining teeth and other surrounding soft tissues.

9. Pressure–pain threshold • The sensation of pain is the most direct indication of a maladaptive denture or a prosthesis to the mucosa. • High contact pressure can cause pain in the mucosa. The contact pressure here refers to the load borne perpendicularly on the mucosal surface. • Patients with a thin mucosa covering sharp bony ridges are more likely to have a lower pressure-pain threshold than those with a thick mucosa over a flat bone surface under a denture base. • The loading locations, such as the palatal, lingual and buccal mucosa, have their different morphologies, thickness and anatomical features, leading to the various pressure-pain thresholds observed

10. TYPES OF ORAL MUCOSA

11. REALEFF EFFECT The oral mucosa on which the complete dentures are fabricated is displaceable and compressible. It is called as Realeff effect or Resiliency like effect.

12. MUCOSAL PATHOLOGIES OF ORAL PROSTHESIS Due to REMOVABLE PROSTHESIS Mucosal lesions Burning mouth syndrome Allergic response Fungal infections Trauma

13. Due to FIXED PROSTHESIS Secondary caries Pulpal and Periodontal infections Allergic reactions Occlusion related disorders Periimplantitis

14. REMOVABLE PROSTHESIS

15. MEAN AREA OF MUCOSA AVAILABLE FOR DENTURE SUPPORT; MAXILLA-22.96 cm2 MANDIBLE-12.25 cm2

16. ETIOLOGY Multifactorial DIAGNOSIS Presence of mycelia or pseudohyphae in the direct smear in large numbers. TREATMENT Oral and denture hygiene Using disinfectant solutions to soak the denture. Remove denture at night Treating any underlying systemic conditions

17. Correction of ill-fitting denture. Rough areas should be smoothened and relined with tissue conditioners. Antifungal therapy: For 4 weeks. Surgical elimination of deep crypt formation in type 3 denture stomatitis.

18. FLABBY RIDGE

19. Excessive forces by unstable occlusal condition can cause flabby ridge which provides poor support for the denture. Caused by replacement of underlying supporting bone by fibrous tissue. Common in anterior maxilla.

20. MANAGEMENT : Conservative approach Prosthetic approach Surgical approach.

21. CONSERVATIVE APPROACH: Tissue rest. Soft tissue massage. Modification of the denture by Flange and occlusal adjustment. Tissue conditioning.

22. PROSTHETIC APPROACH: 1. Impression. 2. Centric occlusion record 3. Occlusal form and posterior teeth arrangement.

23. SURGICAL ABLATION: Removal of fibrous tissue to leave a firm ridge. May recur. Results in elimination of vestibular sulcus.

24. DENTURE HYPERPLASIA Also known as Epulis fissuratum . Contains flaps of hyperplastic connective tissue.

25. MANAGEMENT : Removing offending denture or shortening the overextended flange to aid in tissue rest. Denture is corrected with soft liners or tissue conditioning agents. Surgical removal is attempted only if other approaches fails.

26. Gagging • Stimulation of sensitive areas in posterior pharyngeal wall, soft palate, uvula, fauces or the posterior surface of tongue results in series of uncoordinated and spasmodic movements of swallowing muscles. This is referred to as gagging . • Usually, this may be due to a denture that is too loose, too thick or extended too far posteriorly onto the soft palate . • Stimuli such as sight, taste, noise, as well as psychological factors, or a combination of these, may trigger gagging . • In wearers of old dentures, gagging may be a symptom of diseases or disorders of the gastrointestinal tract, adenoids or catarrh in the upper respiratory passages, alcoholism, or severe smokin

27. TRAUMATIC ULCER Develop within 1-3 days after placement of new dentures. Also known as sore spots. Causes- overextended denture or unbalanced occlusion. Predisposing factors- diabetes ,nutritional deficiencies, radiation therapy, xerostomia .

28. MANAGEMENT: In the systemically non-compromised host, sore spots will heal after correction of the denture. If no treatment is instituted, patient will adapt to the painful situation while will develop into denture irritation hyperplasia .

29. ANGULAR CHELITIS Also known as angular cheilosis , perleche . Affecting the corner of the lips. Predisposing factors include infections, nutritional deficiencies and reduced vertical dimension of the mouth.

30. MANAGEMENT: Evaluation of the predisposing factors. Topical anti fungal ointment or cream. Replacing with a new denture to modify the face vertical dimension. Follow up.

31. ORAL CANCER An association between oral carcinoma and chronic irritation of the mucosa by dentures has often been claimed, but no definite proof seems to exist. Continuous trauma chronic inflammation Panat et al;Denture induced squamous cell carcinoma: a rare case report. Journal of oral science and health; April 2012

32. Management • Any persistent sore spot remaining even after the correction of dentures are often suspected for malignancy. • Regular recall visits at duration of 6 months has to be followed for comprehensive oral examination . • Treatment for oral cavity cancer is based largely on the stage (extent) of the cancer- chemotherapy, radiotherapy and surgical resection.

33. BURNING MOUTH SYNDROME 5-7 % of denture wearing population. ETIOLOGY: Local factors Systemic factors Psychogenic factors

34. Management • Identifying the causative factor is important and it should be removed. • Vitamin therapy is provided when associated with its deficiency . • If psychogenic / psychosocial disturbance are diagnosed, adequate treatment should be offered through counselling and use of tranquilizers if required

35. ALLERGIC REACTIONS Hypersensitivity to resins. Denture wearers suffer from burning sensation in the mouth or in the tongue. S imilar to burning mouth syndrome. Dysgeusia Bitter or metallic taste in the mouth .

36. MANAGEMENT; Treated symptomatically until the mucosa heals. Properly heat cured acrylic resins are recommended. Indirect methods are preferred when fabricating autopolymerising temporary prosthesis. Choudary et al. Contact Allergy to Denture Resins;2016 International journal of oral implantology and Clinical Research 7(2):40-44

37. FIXED PROSTHESIS

38. GINGIVAL RESPONSE TO CROWNS AND BRIDGES Localised gingival irritation caused by excess cement.(Artificial calculus) Corelation - gingival inflammation and distance of the crown margin below the gingival crest. Gingival hyperplasia- subgingivally placed restoration margin.

39. Gingival hyperplasia – subgingivally placed restoration margins. MANAGEMENT: Patient education Maintenance of oral hygiene. Re-fabrication of the prosthesis.

40. PERI-IMPLANT DISEASE Peri -implant mucositis : Peri-implantitis

41. PERI-IMPLANT MUCOSITIS: Accumulation of bacterial biofilms Disruption of host –microbe homeostasis Clinical signs- Redness, swelling, bleeding on gentle probing and suppuration.

42. PERI-IMPLANTITIS: Progressive loss of peri -implant bone. F ollowing initial loading ,some 0.5 to 2 mm of crestal bone is lost.

43. TREATMENT APPROACHES Mechanical debridement of biofilm and calculus. Occlusal therapy. Local or systemic antimicrobials Peri-implantitis Update: Risk Indicators, Diagnosis, and Treatment. European Journal of Dentistry .

44. Implant surface decontamination . Flap surgical intervention. Regenerative approach.

45. CONCLUSION

46. REFERENCES: Boucher 12 th edition, Sequalae of complete denture. Shafer ; Textbook of oral pathology ed 7th ; Mucosal response to oral prostheses . Chen J, Ahmad R, Li W, Swain M, Li Q. 2015 Biomechanics of oral mucosa. J. R . Soc. 2015; Interface 12: 20150325 Figuero , E., Graziani , F., Sanz , I., Herrera, Management of peri -implant mucositis and peri-implantitis . Periodontology 2000, 66(1), 255–273 . Heitz -Mayfield , 2008; Diagnosis and management of peri -implant diseases. Australian Dental Journal, 53(s1), S43–S48. Choudhary et al. Contact Allergy to Denture Resins; 2016 International Journal of Oral Implantology and Clinical Research 7(2):40-44